Project: The Microbiome and Human Decomposition
University Association: Sam Houston State University
Collaborator Name: Sibyl Bucheli, Ph.D. and Aaron Lynne, Ph.D.
Decomposition is a mosaic ecosystem where an intimate association between biotic factors (such as the corpse, intrinsic and extrinsic bacteria, and insects) and abiotic factors (such as weather and climate) exists. Despite the integral role of bacteria in the decomposition process, very little is understood regarding the bacterial basis of decomposition or its function in insect recruitment (or repulsion) to a corpse. Our research links together disparate areas of biology, chemistry, and forensics allowing us to test our ultimate hypothesis: that bacterial species guild changes over time drive decomposition and fundamentally modulate the tempo and mode of decomposition.
Our research aims to characterize the microbiome of the human body through the entire decomposition process by:
- Identifying bacteria significant to the decomposition process of the body, introduced by the soil, and introduced by flies
- Collecting and characterizing gasses emanating from the cadaver at different times during decomposition
- Correlating species of insects present with bacteria present by linking them through their bacterial gaseous by-products
- Designing specific and novel comparative and forecasting models to characterize bacterial and insect succession through time, which will ultimately aid in estimation of the postmortem interval through providing a more precise method of analysis.
With the help of Dr. Joe Petrosino and the Baylor College of Medicine Alkek Center for Metagenomics and Microbiome Research, we have begun to show that the microbiome changes over time and may be integral in the modulation of rate of decomposition.